1. Field of the Invention
The invention relates to the field of apparatus and method utilizing light emitting diodes (LED) in an improved apparatus and method of collecting the energy radiating from them.
2. Description of the Prior Art
In the prior art either a lens or a reflector are used to collect the substantially 180 degree hemispherical light radiating from the LED. Total internal reflection (TIR) is also used where the energy from the LED is collected both by an internal shaped reflector-like surface of the lens and a lens formed on either the outside or inside surface of the lens as shown in Marshall U.S. Pat. No. 6,547,423.
Devices using a reflector alone generate two beams, one beam is reflected and controlled by the reflector and one beam is direct radiation from the LED and is not controlled. This direct light may appear as a large halo around the reflected beam. In the typical LED ‘package’ with a ball lens situated in front of a cylindrical rod, the side emitted energy from the LED is substantially uncontrolled. In TIR systems, some portion of the energy radiating from the LED is leaked through the walls of the package and remains uncontrolled. Additionally, there are bulk and form losses. In systems with LEDs reversed and pointed into a concave reflector, the center energy from the LED is shadowed by the LED package itself, so this energy is typically lost or not collected into a desired beam.
What is needed is some type of apparatus and method of illumination wherein each of the defects of the prior art are overcome.